Coating for paper and method of production



Patented July 10, 1951 COATING FOR PAPER AND METHOD OF PRODUCTION Louis J. Scheid, Watervliet, Mich., assignor to Watervliet Paper Company, Watervliet, Mich.

No Drawing. Application February 6, 1947, Serial No. 726,953

8 Claims. 1

This invention relates to improvements in a Coating for Paper and Method of Production.

The main objects of the invention are:

First, to provide an improved coating for paper which includes as an ingredient thereof soy bean hour, so treated as to solubilize the carbohydrates of the flour and to thereby reduce the viscosity thereof.

Second, to provide an improved coating of the type above described which results in a more satisfactory sheet, both from the standpoint of operation in the mill as well a improving the surface characteristics, such as to color, smooth ness, gloss and ink receptivity.

Third, to provide an improved method of producing a coating of the type above described.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is pointed out and defined in the claims.

As a step in carrying out the invention, soy bean flour, one of the ingredients of the paper coating, is solubilized and rendered less viscous to facilitate mixing of the same with the other ingredients of the paper coating, the application of the mixed paper coating to the sheet of raw paper stock, the operation of the coated raw stock in the mill, and the production of an improved surface to the paper for printing purposes. In solubilizing the soy bean flour the following ingredients are used in approximately the proportions indicated:

Parts Dry soy flour (Pur. Wt.) 45.0 Water 210.0 Enzyme (Amyliq) 0.1 5% Caustic soda solution 45.0

The 210 parts Water, as parts soy flour and 0.1 part amyliq enzyme are first mixed with each other. So mixed the enzyme is allowed to act on the soy flour for 60 minutes at 120 F., after which the 45 parts of 5% caustic soda solution i added. The solution with the caustic soda added is held at 126 F. for 30 minutes and then strained which gives a final solution in the ratio of 15 parts purchase Weight of soy flour per 100 parts of solution. The soy flour used contains soy bean protein. In the trade a flour of such type is known as Archer Daniels Midland K Soy 6 Flour.

The viscosity of the final solution converted as above prepared compared to that of a solution not acted upon by the amyliq enzyme and not converted, but otherwise similar thereto as tested on a Stormer viscosity tester, is as follows:

As indicated by the above figures the solution of the enzyme converted flour is much less viscous than that of the unconverted soy flour solution.

The above enzyme converted solution is then used as one of the ingredients in a paper coating solution, the ingredients of such coating solution and the relative proportions thereof being approximately as follows: 50 parts of clay, 36.6 parts of water, 79.4 parts of the enzyme converted soy solution. This gives a coating containing 37.2% solids. As an ingredient of this paper coating solution the enzyme converted solution being much less viscous than the nonconverted solution great- 1y facilitates mixing the same with clay in producing the final paper coating mixture. With a non-converted solution of soy flour it is necessary to thin the same with water to a very high degree in order to mix with the clay, and when so diluted with water to mix with the clay, the coating so formed contains hard crystalline lumps that make the coating rough and hard to polish and render the coating inferior from the printers standpoint. These crystalline lumps appear to be the insoluble carbohydrates in the soy flour that swell when Wet.

Not only does the enzyme converted soy flour solution facilitate mixing the ingredients of the paper coating mixture or solution as above described but also renders the paper coatin mixture or solution so prepared less viscous, thus facilitating application of such paper coating solution to the raw paper stock in the milling operation. The relative viscosities of two paper coating solutions, one including the enzyme converted soy solution and the other including the non-converted soy solution, were tested on a Stormer viscosity tester with the following results:

The paper coating mixture prepared as above described including the enzyme converted soy flour is coated onto the raw paper stock and calendered in the milling operation and as compared to that produced by coating with the mixture including the non-converted soy flour is much more satisfactory, not only from the standpoint of operation in the mill but also from the standpoint of surface characteristics for printing purposes.

A coating mixture prepared as above described including the converted soy flour and another coating mixture includin the non-converted soy flour but otherwise similar to the first mixture were coated onto stanard raw stock and the resulting sheets calendered and tested. The results were as follows:

The process of solubilizing the carbohydrates in the soy flour by the addition of the enzyme facilitates the preparation of the coating mixture, the application of the coating mixture to the raw stock, the operation of the coated stock in the mill and results in a paper with improved surface characteristics such as to color, smoothness, gloss and ink receptivity.

Amyliq belongs to the class of enzymes designated as amylases or amylolytic enzymes.

Amyliq is the trade name of the enzyme and is produced by the Wallerstein Company of New York, N. Y. It belongs to the class of enzymes designated as amylases. They have the property of solubilizing carbohydrates and thereby reducing them to simple sugars. Soy flour is approximately 50% protein, the balance of the flour being largely soluble sugars and mucilaginous products. The first step above described, to wit, that of allowing the amyliq enzyme to act on the soy flour in water for 60 minutes at 120 F. solubilizes the mucilaginous products and reduces them to simple sugars. The second step above described, to wit, that of adding caustic soda solution to the enzyme treated solution and holding the same for 30 minutes at 120 F. solubilizes the protein. When the soy flour in wateris not solubilized with amyliq enzyme the 'mucilaginous products remain present in the solution in the form of suspensoids. These are small jelly-like pieces that in many respects resemble tapioca. This causes the solution to have jelly-like characteristics, and renders it very difdcult to mix with clay or other pigments in preparing coating mixtures. They are also present as crystalline lumps after the coating has dried on the paper, and cause the sheet to have a rough granular surface and interfere with ink absorption when the paper is printed. The above described step of solubilizing the mucilaginous content of the soy flour overcomes these defects and results in a greatly improved final product and facilitates the ready production of the same as heretofore described.

I have disclosed my invention in embodiments or adaptations thereof which I have found highly efiicient. I have not attempted to disclose other embodiments or adaptations thereof as it is believed this disclosure will enable those skilled in the art to embody or adapt my invention as may be desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

i. In the process of producing a coating composition for paper, characterized by a high degree of smoothness and by improved ink receptivity, the steps of solubilizing soy bean flour in water by adding an amylolytic enzyme to solubilize the mucilaginous content of the soy flour to render the solution less viscous and to prevent formation of hard crystalline lumps, solubilizing the protein content of the soy flour by the addition of an alkali to the water to render the solution less viscous, and mixing the resulting solubilized soy flour solution and a filler of earthy material to form a coating mixture for paper.

2. In the process of producing a coating composition for paper, characterized by a high degree of smoothness and by improved ink receptivity,

the steps of solubilizing soy bean flour in water by adding an amylolytic enzyme to solubilize the mucilaginous content of the soy flour to render the solution less viscous and to prevent formation of hard crystalline lumps, solubilizing the protein content of the soy flour by the addition of an alkali to the water to render the solution less viscous, and mixing the resulting solubilized soy bean flour solution and a filler of clay to form a paper coating mixture.

3. In the process for producing a coating composition for paper, characterized by a high degree of smoothness and improved ink receptivity, the steps of solubilizing soy bean flour in water by adding an amylolytic enzyme to solubilize the mucilaginous content of the soy flour to render the solution less viscous and to prevent formation of hard crystalline lumps in the solution, and by adding an alkali to the water to solubilize the protein content of the flour to render the solution less viscous, said enzyme being amyliq.

a. In the process of producing a coating com position for paper, characterized by a high degree of smoothness and improved ink receptivity, the steps of mixing soy bean flour, water, and an amylolytic enzyme together, said enzyme solubilizing the mucilaginous content of the flour and rendering the solution less viscous and preventing formation of hard crystalline lumps in the solution, said water having in solution an alkali to solubilize the protein content of the flour.

5. A coating composition for paper, characterized by a high degree of smoothness and improved ink receptivity, consisting essentially of soy bean flour and a filler of clay, said soy bean flour being the product resulting from solubilizing the protein content of soy bean flour with an alkali and solubilizing the mucilaginous content of the flour with an enzyme, said enzyme being amyliq.

6. A coating composition for paper, characterized by a high degree of smoothness and improved ink receptivity, consisting essentially of soy bean flour and a filler of clay, said soy bean flour being the product resulting from solubilizing the protein content of soy bean flour with an alkali and solubilizing the mucilaginous content of the flour With an amylolytic enzyme.

A P per having a coating, characterized by a high degree of smoothness and by improved ink receptivity, said coating consisting essentially of an earthy material and a product resulting from. solubilizing the protein content of soy bean LOUIS J. SCHEID.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date Taucks et al May 19, 1931 Satow Sept. 22, 1931 Cone et al June 12, 1934 Oberg June 24, 1941 Craig Oct. 24, 1944 Julian et a1 Nov. 28, 1944 Clark Mar. 5, 1946 Dunham Dec. 3, 1946 FOREIGN PATENTS Country Date Great Britain June 21, 1928 OTHER REFERENCES Markley 8: Goss, Soybean Chem. & Tech. (1944) pp. 21 and 22. 

1. IN THE PROCESS OF PRODUCING A COATING COMPOSITION FOR PAPER, CHARACTERIZED BY A HIGH DEGREE OF SMOOTHNESS AND BY IMPROVED INK RECEPTIVITY, THE STEPS OF SOLUBILIZING SOY BEAN FLOUR IN WATER BY ADDING AN AMYLOLYTIC ENZYME TO SOLUBILIZE THE MUCILAGNINOUS CONTENT OF THE SOY FLOUR TO RENDER THE SOLUTION LESS VISCOUS AND TO PREVENT FORMATION OF HARD CRYSTALLINE LUMPS, SOLUBILIZING THE PROTEIN CONTENT OF THE SOY FLOUR BY THE ADDITION OF AN ALKALI TO THE WATER TO RENDER THE SOLUTION LESS VISCOUS, AND MIXING THE RESULTING SOLUBILIZED SOY FLOUR SOLUTION AND A FILLER OF EARTHY MATERIAL TO FORM A COATING MIXTURE FOR PAPER. 